The research proposal will address six objectives relating to patients with irritable bowel syndrome in comparison to patients with similar symptoms from chronic inflammatory bowel disease (CIBD). The objectives are the ascertain whether IBS patients: 1) More frequently have psychiatric disorders than CIBD patients. 2) Manifest certain gastrointestinal and psychiatric symptoms which can discriminate them from CIBD patients. 3) Demonstrate a closer correlation of mood to variations in frequency and intensity of gastrointestinal symptoms than do CIBD patients. 4) Show a greater improvement of their gastrointestinal and psychiatric symptoms in response to desipramine than to a placebo. 5) Show a greater improvement of their gastrointestinal and psychiatric symptoms in response to disipramine than do CIBD patients. 6) Reveal a greater correlation between objective - physiological and subjective-perceived improvement in their gastrointestinal and psychiatric symptoms in response to desipramine than do patients with CIBD. The symptomatic attributes will be quantifiably recorded in a diary by the patients. Psychiatric status will be objectively assessed by testing and structured interviews. Rectosigmoid manometry will be performed by a standardized technique. Desipramine and placebo effects on the attributes will be measured through the double blind cross-over method during 8 week periods. A comparison of response to the drug and placebo will be made within and between the groups with IBS and CIBD.